Display screen or portion thereof with an animated graphical user interface



FIG. 1 is a front view of a display screen or a portion thereof with an animated graphical user interface showing a first image in a sequence according to our new design;

FIG. 2 is a second image thereof; and,

FIG. 3 is a third image thereof.

The outermost broken-line rectangle illustrates the perimeter of a display screen or portion thereof. The remaining broken lines illustrate portions of a graphical user interface. The broken lines form no part of the claimed design.

The appearance of the display screen or portion thereof with an animated graphical user interface sequentially transitions between the images shown in FIGS. 1-3. The process or period in which one image transitions to another forms no part of the claimed design. 

CLAIM The ornamental design for a display screen or portion thereof with an animated graphical user interface, as shown and described. 